Combining Radar and LoRaWAN: Building some sort of "presence detection counting device"

Gerhard Peter


Posted on 24-03-2018

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A few days ago, we could read about the phantastic "Paxcounter", using cutting-edge technologies, here and could follow a discussion in the TTN forum, too. There arised a lot of questions about "personal data security" and "data protection". And yes, we all listen to Zuckerberg these days... Even if data are not collected - and it would be impossible transmitting all data via LoRaWAN, because of limited capacities- and stored for long time, some sophisticated guys argued, that even "catching MAC adresses for only a microsecond" - and hashing and salting them instantly- would be 'against law'. Those guys really seem to have lost ground - maybe they are right, maybe not.

Meanwhile another approach for another usecase came into my mind. While following these discussions, i discovered, by chance, a ridiculous cheap radar sensor chip (RCWL-0516) and had a look @ specs. Looking good, so it should be possible to combine an ESP/TTGO v2.0 with such a radar sensor and of course a battery or solar..... making some sort of "presence detection counting device".

Here in Berlin-Mierendorffplatz, we have this public "BookBoXX" (see picture taken by me) everybody can use as a public exchange point for books. "Bring-one | Get-one". And yes, this old fashioned mode works phantastic. Not everybody uses an e-reader...

Because of the enormous political interest in these project, it would be nice, getting reliable data about using frequency of this stand alone box. There is solar on the roof top, that could be used for supplying energy necessary.

If you are interested, you may have a deeper look, even make one. This is still work in progress. And yes, in Berlin we have nearly full TTN coverage in inner city.